1. Field of the Invention
The present invention relates to a facsimile apparatus having communication compatibility with a transmission-reception mode informed of from another apparatus interconnected thereto.
2. Description of the Prior Art
Facsimile apparatus are classified into high-speed machines, middle-speed machines etc., according to the time period required for transmission. For example, for the middle-speed machines the GII Standard regulated by CCITT (The International Telegraph and Telephone Consultative Committee) recites the use of A-4 size for an original document picture to be transmitted and for recording paper. For this reason larger originals, for example, of B-4 size, cannot be handled by the GII standard apparatus though such larger originals may frequently be encountered. Also some conventional facsimile apparatus have a function of automatic picture reception without manual operation. Such pictures automatically received may not however be noticed by the attendant of the receiving unit and information requiring urgent responsive may not therefore be handled properly, because the receiving subscriber cannot be called by the calling party by way of preliminary telephone talk before picture transmission where the receiving apparatus is in such an automatic reception mode. Also for the purpose of communicating the conditions of a received picture after the picture transmission, the telephone handset may often be left off-hooked after the picture transmission for maintaining the telephone line in its connected state, but the operator may sometimes have forgotten such off-hook as telephone talk request cannot be reserved or memorized in advance. Although such situation may seem rather strange, the attendant of the apparatus may in fact forget the off-hooked handset because of other jobs which may be made during a period of several minutes after the start of picture transmission.
FIG. 1(a) indicates the tonal signals emitted by the transmitter and the receiver according to the aforementioned GII Standard.
In FIGS. 1(a) to 1(d) the line L is the time axis from top to bottom, and the tonal signals emitted from the transmitter and from the receiver are respectively indicated at the left and right sides of the line L. The frequency and duration of each of the signals CED (called station identification), GI II (group identification II; for confirming GII apparatus), GCII (group command II; for designating GII apparatus), LCS (line conditioning signal), PH (phase signals), CFRII (confirmation to receive II; for confirming the preparation for reception), PIX (picture signals), EOM (end of message), MCFII (message confirmation II; for confirming the message in GII Standard), and GI II (mentioned above) are summarized in the following Table I:
TABLE I ______________________________________ Frequency Duration Frequency Duration ______________________________________ CED 2100 Hz 3 sec CFR II 1650 Hz 3 sec GI II 1850 1.5 PIX 2100 ca. 180 (carrier) LCS 1100 1.5 MCF II 1650 3 PH 2100 6 ______________________________________